Chris, I've been using the ST-34H motors for several years and infact, just bought a used one for additional planes that I have. I've used this motor in carrier as I can get 17,800 out of a 9-6 and still get a good low speed for the event. I recently put this motor on my ASTRON stunt bird to see how it would do. Mind you, I did not remove the carb. Just locked the carb open and adjusted the needle valve for a good run. I was surprised how well it ran using a 10-6 for the 54" W.S. plane. Not much of a 4/2 break to speak of but plenty of power thru all manuevers that I can do. Overhead eights were fine with plenty of power on the top. I've never used a prop larger than 10-6 on this motor, so I really don't know how else it would perform. If you come up with a venturi for this motor, I would be very interested in acquiring one or two of them for the other motors. For a ringed motor, I think Super Tigre did a great job. One of my 34's was reworked by Randy Smith when I first bought it and it is still running on the first ring! and that was at least 8 or so years ago. I also tear it down every year for complete cleaning and inspection. I have replace the rod only once in this time frame. I don't think timing is a problem. Some of the engine experts would know more on this subject. Leonard could probably add to this subject with great expertise. Please let me know on the venturi you're working on.
